ok, i'm going to buy the flange from racing beat, but i need to know whats the best exhaust pipe to use to make this manifold for it wont crack

Stainless steel, 5mm wall and good welds

is that the only material that can be used?? and will that be able to be welded to the steel flange.

Right on, you can also you mild steel..

Mild steel is not good to use due to the corrosion properties..

SS expands and contracts more more than mild steel so that has to be considered in the design process, although its not that big of a deal on rotaries cause there is only two exh ports and the manifold is fairly small.

Stainless wont crack as long as you use thick enuogh material and dont under-cut the welds too bad

321 stainless has better heat strength than 304. Inconel is the pimp daddy of manifold materials.$$$$



Burns Stainless

According to the site it is a little more difficult (different) to weld so probably wouldnt be a good idea unless you have some experience welding...mabey I'll get some and try it out https://www.nopistons.com/forums/pub..._DIR#>/dry.png

Schedule 40 , steel pipe and elbows . works great , is cheap and easy to weld . Myself and many have been using this down here without any problems (corrosion and other wise).

Inconel gives you HUGE puddles around the welds

Metal steam piping always does the trick to.

I used schedule 10 304L SS. If you already have the steel flanges I'd use regular sch 40 pipe with weld el's from mcmaster.com They are cheep and will outlast your car.

This is it, don't run your WG runners as early out of the manifold as i did. Right now I'm having boost creep issues even using a 46mm wg. I think it's because I tapped in too early to the main runners.



https://www.nopistons.com/forums/upl...1049682377.jpg

Here you can see the WG runners a little better.



Becides the creep issue the manifold is working awsome. Great boost responce, I think the equal length and divided manifold/turbo is really the only way to go.



https://www.nopistons.com/forums/upl...1049682015.jpg

That is a pretty manifold. Did you weld that yourself?

I did it all except machine out the SS flanges. I like having a machinist for a friend https://www.nopistons.com/forums/pub...IR#>/smile.png

That kicks ass man. You did a very nice job, I wish my welds were that even.





How many times did you go over that?

Thanks

What do you man "go over"? I layed 1 bead per weld, no more. Actually I used the fusion method for most of the manifold. Only used a little filler rod here and there when needed. Thats the beauty of SS, it fusion welds awsome. I can't weld mild steel very well and forget about aluminum...

Ahhhh so thick ss welds just like really thin ss. You just tack it in a couple spots, and melt the joint togather.







What I meant by go over is stitch welding basically. You make your filler pass, then you go back over it with the machine turned down. You can make circles, or x's. Yours looked like you did the x pattern.







Mild steel is easy, you have the skills to do it. Just practice at it a bit.





Aluminum is mostly based on machine settings. If you can't get the machine right, the welds will never be right.





All it takes is knowlege and practice.

I tacked the two main runners together then welded them with one pass per joint. Then I fitted the two main runners into the flanges and welded them. I did the WG plumbing last.



I was just borrowing my friends TIG welder and really had no idea how to TIG at the time. I practiced on some scrap and them felt confident enough to go ahead and do the job.



At first I was trying to purge the runners with gas but soon found out that wasn't needed because of the thick wall of the sch 10 pipe (~1/8"). I was told to purge but I think that may be more importiant when welding thin tubing ss.



I understand what you are saying with the practice comment. Learning to weld with the TIG takes a lot of it unlike MIG.

It sounds like you did everything right. I'll have to try making one with ss. I haven't done that yet.







Mig = metal hot glue gun. I only use our mig to tack intercooler tubing togather. Nothing else. I hate mig.







Purging the stuff that you are welding... That brings up a whole giant argument. I do not purge anything. It is a waste of gas.





Go talk to some people that have been welding for 20 years. Ask them what they think about it.

haha, if I could TIG everything I would. I like my little MIG for doing exhaust and things like that.



I was told purging was only needed when welding SS. I did try it and I did notice a decrease in cyrstal like drop through on the inside. I found a good heat range and minimized any dropthrough so I stopped purging.

Yeah, that about covers it.





Purging is good if there are huge gaps that you are trying to fill in. But if your joints are set up right there is no need for it.

I suspect boost creep is less to do with manifold design and more to do with the turbo that's almost bigger than the motor!

I have welded Inconel with both oxy and TIG (making thermocouples but thats another story!)

It is hard weld at first, much more than mild, but with practice comes ease grasshopper, and the stuff is hell tough. The temperatures need to be just right for the best results

I have welded Inconel with both oxy and TIG (making thermocouples but thats another story!)

It is hard weld at first, much more than mild, but with practice comes ease grasshopper, and the stuff is hell tough. The temperatures need to be just right for the best results [/quote]

I have a couple of stupid questions.





Can you weld inconel to steel?



What shielding gas do you use?





Also, have you ever welded titanium? https://www.nopistons.com/forums/pub...#>/biggrin.png

Not a stupid question at all.

You can pretty much weld anything to anything.

You can join Inconel to mild, we have done it here in an application that was very tightly budgetted (not auto). Used inconel in the hot area and switched to mild further away. The cast mild elbows in the previous pix are fine for exhausts. Heavier, but cheap & durable



Have tried welding Titanium with limited success, again just lack of experience. I'd just LOVE to do some car bits in titanium.



Gas is Argon in all cases. I use BOC Argoshield 54 (May not be called that in the States!). A bit more expensive, but you notice a good gas!

just a pic for Zero R to look at

Cool, thanks for the answers. I think that I am going to play with some titanium tommorow. https://www.nopistons.com/forums/pub...#>/biggrin.png I already use argon for everything, so I am good on gas.

Cool!

Post with your results https://www.nopistons.com/forums/pub...IR#>/bigok.gif

I will. https://www.nopistons.com/forums/pub...>/bigthumb.gif